This one-way, mostly downhill run leads past Undine Falls, through Lava Creek Canyon, along the Gardner River, and up to the highway near Mammoth. Along the way enjoy great views and good wildlife viewing opportunities. The trail’s relatively low elevation make it a excellent early-in-the-season run.
Although you can run this trail as an out-and-back, it is best done as a shuttle if you can arrange to be picked up at the Mammoth to North Entrance Road.
This one-way, mostly downhill run begins at Lava Creek Picnic Area on the Mammoth to Tower Road and ends on the Mammoth to North Entrance road, about a 1/2 mile from Mammoth Hot Springs.
The trailhead is just across the road from Lava Creek Picnic Area. Less than .1 mile from the trailhead, the trail reaches a junction with the Blacktail Ponds Spur Trail
. Turn left here and continue through sagebrush meadows for .4 miles. As the trail passes between a stand of trees and Lava Creek, listen for the sound of falling water and look for people viewing Undine Falls from the opposite side of the creek. Visitors can view it too, just off the trail to the left (but be careful there are no guardrails here).
Undine Falls is a beautiful three-step, 60-foot waterfall that once graced the cover of National Geographic magazine (in 1977). It was named by early park geologist Arnold Hague. In German mythology, water spirits (Undines) inhabited beautiful waterfalls and could capture the souls of mortal men by marrying them. Hague also named Lava Creek, for the basaltic and rhyolitic lava flows that abound in the area.
Just past the falls, the trail bends to the right and affords impressive views of Lava Creek Canyon and the Mammoth Hot Spring Terraces beyond. At the .6-mile mark, the trail enters the trees and begins an 800 foot drop (steeply at first) over the next 2 miles. The forest is a mix of spruce, fir and lodgepole pine. At the 2.7-mile mark the trail passes an open area on the left beneath the high highway bridge. Here Lava Creek joins the Gardner River, named for Johnson Gardner, who trapped beaver in the area in the 1830s.
For the next mile, the trail closely follows the Gardner River. Watch for elk and buffalo here. Also, watch the sky above you for osprey (or fish hawks) or even bald eagles patrolling up and down the river looking for a meal of brook trout. To your right is Mount Everts, made up of distinctly layered sandstones and shales – sedimentary rocks deposited when this area was covered by a shallow inland sea, 70 to 140 million years ago. At the 3.9-mile mark the trail makes a left turn and crosses the Gardner River on a steel suspension bridge (sorry, no horses allowed).
From the bridge, the trail climbs up the hill and makes a right turn (ignore the trail to the left leading to a park maintenance area), then meanders up and down along the river. At the 4.3-mile mark, the trail veers to the left, away from the river, and begins a 170-foot climb to the highway over the trail’s last .4 miles. Just past the 4.4-mile mark, where the trail makes a sharp switchback to the left, ignore the trail to the right (which leads to the Boiling River swimming area). The Lava Creek Trail ends on the Mammoth to North Entrance Road, not far from the Mammoth Hot Springs Camp Ground.
Thanks to guidebook author, Tom Carter, for sharing this trail description. To learn more about visiting Yellowstone, check out his book, Day Hiking Yellowstone
There's a good chance to see buffalo and elk around the Gardner River near the end of the trail. I've also seen black bear and whitetail deer in the first mile of the trail.